Preliminary question: where is stored the default server which is used by the command systemctl start openvpn (assume sudo, of course)? It should be in /etc/default/openvpn, like it used to be for SysV, but if I change it systemctl still connects openvpn to the old server.
Now for the main question.
According to Using OpenVpn with systemd and also Correct way of systemd for Openvpn (and other sources) if I have two different servers for my vpn (say, London and Paris) then I need the two config files /etc/openvpn/London.conf and /etc/openvpn/Paris.conf so that I can start the server of my choice with systemctl start openvpn@London or systemctl start openvpn@Paris.
Ok, this works.
Now assume I have two different vpn providers (P1 and P2), both with a server in London and one in Paris. One way to set the config files could be
/etc/openvpn/P1_London.conf
/etc/openvpn/P1_Paris.conf
/etc/openvpn/P2_London.conf
/etc/openvpn/P2_Paris.conf
and then I should start openvpn accordingly.
What I would like to do, instead, is to have the conf files in separate directories, one for each provider:
/etc/openvpn/P1/London.conf
/etc/openvpn/P1/Paris.conf
/etc/openvpn/P2/London.conf
/etc/openvpn/P2/Paris.conf
If I do like that and then I try to start systemctl start openvpn@P1/London or any other variant for other servers, I get an error.
The question is: how can I get what I want?